Is die casting cheaper than CNC machining for large production runs?

But one of the most critical decisions in producing metal parts in large quantities is selecting the production process to use. Die casting and CNC machining are two of the most popular techniques. Both have their own merits, but as the production quantities rise, cost becomes an important consideration.

A question that is asked by many manufacturers, engineers and product designers is whether die casting is cheaper than CNC machining for large production runs?

Yes, in most high-volume manufacturing situations, die casting is much cheaper than CNC machining. But the full solution relies on the cost of the tools, production volume, part complexity, material choice and quality.

This guide will discuss the differences between die casting and CNC machining, and determine when die casting is the superior process for large quantity manufacturing.

Understanding Die Casting

The die casting process is a method of manufacturing when molten metal is forced into a hardened steel mold under high pressure. The part is ejected after solidification, leaving a very close-to-net-shape with high levels of consistency.

These are the most common die-cast materials:

• Aluminum alloys
• Zinc alloys
• Magnesium alloys
• Copper-based alloys

Die casting is very efficient for large-scale production, since the mold is used thousands, even millions, of times.

Advantages of Die Casting

• Fast production cycles
• High dimensional consistency
• Excellent surface finish
• Reduced material waste
• Suitable for complex geometries
• Lower per-unit cost at high volumes

Heavy use of die casting is seen in industries like automotive, electronics, aerospace, lighting, telecommunications and consumer products where large production volumes are required.

Understanding CNC Machining

CNC machining is a subtractive manufacturing technology that involves using a cutting tool that is controlled by a computer to remove material from a block of metal or billet and form the desired shape.

Some of the most popular materials used in CNC machining are:

• Aluminum
• Steel
• Stainless steel
• Brass
• Titanium
• Copper
• Engineering plastics

The flexibility, precision, and capability of CNC machining to create highly customized parts without the use of dedicated tooling make it a highly sought-after method for manufacturing.

Advantages of CNC Machining

• Extremely tight tolerances
• No expensive molds required
• Ideal for low-volume production
• Quick design modifications
• Suitable for a wide range of materials
• Excellent prototyping solution

CNC machining remains one of the most versatile manufacturing technologies available today.

Cost Comparison: Die Casting vs CNC Machining

The primary difference between the two processes lies in how costs are distributed.

Die Casting Cost Structure

Die casting requires significant upfront investment.

Typical costs include:

• Mold design
• Tooling manufacturing
• Process setup
• Quality validation

Depending on the complexity of the part, the cost of a high quality die casting mold is several thousand to tens of thousands of dollars.

Once the tooling has been made, however, the cost of production goes down significantly.

CNC Machining Cost Structure

The initial cost of tooling is quite low in CNC machining.

Rather, there are expenses that are incurred throughout each production cycle:

• Machine time
• Labor
• Cutting tools
• Material waste
• Programming and setup

Each part has to be machined one by one, so the production cost is still relatively high without considering the amount of production.

This difference becomes increasingly important as production quantities rise.

Why Die Casting Becomes Cheaper for Large Production Runs

1. Lower Per-Part Cost

Once the tools have been recovered, parts are cast very rapidly by die casting.

The die casting process can take just seconds to minutes, depending on the part size.

Compared to CNC machining, it can typically be expected to include:

• Multiple operations
• Tool changes
• Longer machine runtimes
• Additional finishing steps

As a result, the cost per part decreases significantly with die casting at higher volumes.

For example:

The larger the production run, the greater the savings from die casting.

2. Faster Production Speed

The high-pressure die casting machine can manufacture many thousands of identical parts in a day.

This high throughput gives rise to:

• Reduced labor costs
• Lower machine costs per part
• Faster project completion
• Increased manufacturing efficiency

Although excellent in precision, CNC machining can generally not match the speed of automated die casting systems.

3. Reduced Material Waste

Only the needed amount of molten metal is used for die casting.

While it can be created by runners and gates, a significant amount can be recycled.

CNC machining is a process that can machine significant volume of material from solid stock.

This creates:

• Metal chips
• Scrap material
• Higher raw material consumption

With high cost metals, material savings can make a significant difference in overall production costs.

4. Less Labor Required

The latest die casting plants use automatic equipment for:

• Mold loading
• Metal injection
• Part removal
• Inspection

This reduces direct labor requirements.

CNC machining often involves:

• Programming
• Fixturing
• Tool monitoring
• Multiple machine setups

Even with automation, labor costs generally remain higher per component.

When CNC Machining May Be More Cost-Effective

Although die casting dominates high-volume manufacturing, CNC machining remains the better choice in certain situations.

Low Production Volumes

If only a few hundred parts are needed, die casting tooling costs may never be recovered.

For example:

• Prototype projects
• Product development
• Pilot production
• Small custom batches

In these cases, CNC machining is often more economical.

Tight Tolerances

Some applications require extremely precise dimensions.

CNC machining can routinely achieve tighter tolerances than standard die casting processes.

Industries such as:

• Medical devices
• Aerospace components
• Precision instruments

often rely on CNC machining for critical features.

Frequent Design Changes

Die casting molds are expensive to modify.

If a product design changes regularly, CNC machining offers greater flexibility because no permanent tooling is required.

Break-Even Point Between Die Casting and CNC Machining

The exact break-even point varies by part design and material.

However, many manufacturing projects see cost advantages from die casting when production reaches approximately:

2,000 to 10,000 units or more.

Beyond this range, the initial tooling investment becomes spread across a larger number of parts.

For example:

• Tooling cost: $20,000
• Production quantity: 100,000 parts

Tooling contribution per part:

$20,000 ÷ 100,000 = $0.20 per part

At this scale, die casting often becomes dramatically cheaper than machining every component individually.

Hybrid Manufacturing Approach

Many manufacturers use both technologies during different stages of production.

A common workflow includes:

Phase 1: CNC Machining

Used for:

• Prototyping
• Design validation
• Functional testing
• Small production runs

Phase 2: Die Casting

Used for:

• Mass production
• Market-ready products
• Cost optimization
• Large-volume manufacturing

This strategy minimizes risk while maximizing long-term profitability.

Industries That Benefit Most From Die Casting

Die casting offers significant cost advantages for high-volume industries, including:

Automotive

• Transmission housings
• Engine components
• Structural brackets
• Battery enclosures

Consumer Electronics

• Laptop frames
• Smartphone housings
• Heat sinks
• Device enclosures

LED Lighting

• Lamp housings
• Heat dissipation components
• Fixture frames

Industrial Equipment

• Pump housings
• Valve bodies
• Motor covers

For these applications, die casting often delivers the lowest total manufacturing cost.

Final Verdict

So, is die casting cheaper than CNC machining for large production runs?

In most cases, yes.

Although a larger capital investment must be made in the tooling for the die casting process, the advantage is that it provides significant cost reduction when the production volumes are higher. The benefits of die casting over other metal forming processes are lower per part costs, faster manufacturing speeds, decreased material waste and increased efficiency.

Though low-volume orders and applications with very tight tolerances are still possible, CNC machining is still the best option for prototypes, custom parts, and low-volume runs. But, die casting is usually the most efficient and cost effective process when producing thousands or millions of identical parts.

Die casting may be the better choice for large production volumes when manufacturers want to lower production costs and still meet the quality standards.